Exploring the science of plants, from the field to the lab

Barbara Thiers

Pressed for Time: Herbaria & Environmental Threats Assessment

Posted in Garden News on November 20, 2019 by Barbara Thiers

Barbara M. Thiers, Ph.D., is the Vice President and Patricia K. Holmgren Director of the William and Lynda Steere Herbarium, and Curator of Bryophytes at The New York Botanical Garden.


Photo of an herbarium specimenHerbarium specimens are one of the very few tangible sources of information about how plants and fungi lived before industrialization, and during each successive period of technological advance since then. Through creative adaptation of technologies developed to address other questions, researchers today can glean information from herbarium specimens about an organism’s physiology, its reproduction, interaction with pollinators, predators and parasites, and the atmosphere around it, for example, the presence of pollutants in the soil and the chemical composition of the air.

Plants have small openings on the undersides of their leaves called stomates that allow Carbon Dioxide (CO2) to enter the leaf for the process of photosynthesis, and allow Oxygen (O2), a byproduct of photosynthesis, to enter to air. A variety of studies have demonstrated that leaves produce fewer of these stomates when CO2 concentrations in the air rise. Examination of stomates on herbarium specimens confirm other evidence that CO2 levels are rising, and help to correlate this rise with other types of climatic and human-mediated events. Assays of plant tissue from herbarium specimens can also help find previously unidentified sources of pollution. Herbarium specimens have been used to track historical levels of radiation and heavy metals to serve as a baseline for pre-pollution conditions, and to assess the reaction of a species to the presence of these compounds. These techniques were used to study long-term effects of known pollutions events, such as the Chernobyl nuclear disaster, or can be used to discover previously unknown contamination events.

Read More

In Love with the Lab: A Review of “Lab Girl”

Posted in Books: Past and Present, Personalities in Science on April 26, 2016 by Barbara Thiers

Barbara M. Thiers, Ph.D., is the Patricia K. Holmgren Director of the William and Lynda Steere Herbarium and Vice President for Science Administration at The New York Botanical Garden.


Lab Girl By Hope Jahren Knopf
Cover image via Knopf

Hope Jahren, the author of the new memoir Lab Girl (Alfred A. Knopf, New York 2016), calls herself a geobiologist. A geologist by training, she mostly studies how soil, water, and climate affect plant growth. After working at a variety of universities, she is currently at the University of Hawaii. In her spare time, she is an active blogger, mostly writing about “interactions between women and men and Academia.”

Lab Girl begins with Hope’s childhood in a small town in southern Minnesota, where her family had lived for generations. Her childhood home life was stable, although her parents were very reserved and Hope received little outward affection from them. Formatively, she spent evenings with her father in his chemistry lab at the local junior college where he taught. From this experience, she developed a love for the order and purposefulness of a laboratory as a venue for discovery and wonder.

The book chronicles Hope’s journey from undergraduate to graduate student, to struggling young professional researcher, and ultimately to successful and acclaimed leader in her field. Many aspects of this story will be familiar, painfully so, to those who began their scientific careers toward the end of the 20th century and also struggled with acceptance by colleagues, the never-ending grind of raising money, institutional politics, and the careful time-management required (especially for women) to balance family and career. Sexism enters the picture, of course, but in describing this, along with the other challenges she has faced, Hope is matter-of-fact and without self-pity. Her creative energy and desire to succeed sometimes outstripped her emotional strength, but she has found a control regimen that seems to keep her balanced.

Read More

A Salute to Jackie Kallunki

Posted in Personalities in Science on February 19, 2015 by Barbara Thiers

Barbara M. Thiers, Ph.D., is the Patricia K. Holmgren Director of the William and Lynda Steere Herbarium and Vice President for Science Administration at The New York Botanical Garden.


Jacquelyn A. Kallunki, Ph.D.
Jacquelyn A. Kallunki, Ph.D.

Jackie Kallunki, Ph.D., first came to The New York Botanical Garden in late 1975 and worked for a while identifying neotropical plant specimens and gathering data for an ethnobotanical project. At that time, she was still working on her Ph.D. dissertation at the University of Wisconsin. After she completed her dissertation, she came back to the Botanical Garden as a full-time employee. And now, I’m sad to say, she has retired.

Over the years, as Jackie rose through the ranks to become Assistant Director of the William and Lynda Steere Herbarium, she worked closely with Patricia K. Holmgren, Ph.D., who was then Director of the Herbarium. This was a very active period in the Herbarium’s history in terms of acquisitions, loans, visitors, and special projects such as the incorporation of orphaned herbaria and expansion of the collection.

The crowning achievement of this period was the planning of the new Steere Herbarium and then moving the multi-million-specimen collection into it. Jackie was the one who figured out how much space each group of plants should receive and where it should go, and she supervised the highly complicated process of moving the specimens to the Herbarium. It took 58 Garden staff, interns, and volunteers a total of about 3,300 hours to accomplish this move. The fact that the process went smoothly and according to schedule is a testament to Jackie’s planning abilities, determination and powers of intimidation!

Read More

Earth Day Everyday: Citizen Scientists Making Plant Research Available to All

Posted in Applied Science on April 21, 2014 by Barbara Thiers

Barbara M. Thiers, Ph.D., is the Patricia K. Holmgren Director of the William and Lynda Steere Herbarium and Vice President for Science Administration at The New York Botanical Garden.


Notes from Nature

Every year around Earth Day, many people wonder if there is anything they can do that will make a difference in the effort to understand and preserve our environment. Of course there is! There are all kinds of volunteer projects for all sorts of interests. Here at The New York Botanical Garden, for instance, volunteers are helping us make a critical part of our scientific collection available online so researchers everywhere can have easy access to the information.

The William and Lynda Steere Herbarium is taking part in a citizen-scientist transcription project called Notes from Nature, which enlists volunteers to help make the contents of the world’s biological collections accessible to the public through the Internet. Notes from Nature is part of Zooniverse, which has enlisted volunteers to look for new planets and transcribe climate data from ships’ logs. Notes from Nature is celebrating its first anniversary this week and also an important milestone: its volunteers have completed a half million transcriptions!

Read More

More Than Peanuts: George Washington Carver’s Fungi Fascination

Posted in Nuggets from the Archives on February 11, 2014 by Barbara Thiers

Barbara M. Thiers, Ph.D., is the Patricia K. Holmgren Director of the William and Lynda Steere Herbarium and Vice President for Science Administration at The New York Botanical Garden. In honor of Black History Month, she reveals a little-known aspect of botanist-inventor George Washington Carver’s work and his connection with the Botanical Garden.


George Washington Carver (1910)

George Washington Carver may be best remembered for his domestication and promotion of the peanut, but the William and Lynda Steere Herbarium contains evidence of another of his contributions—documenting fungal diseases of plants, which, among other things, is an important cause of crop loss on farms.

Carver was born to slave parents on a farm near Diamond Grove, Missouri, around 1864. Although his boyhood was full of struggle against poverty, racism, and illness, his powerful intellect and insatiable curiosity helped him to persevere with his studies. He entered Simpson College in Iowa and then transferred to Iowa State University, becoming the first African-American student to be enrolled there.

After graduation, Carver was appointed assistant botanist at the Iowa State University Experiment Station. His research program in crop diseases brought him to the attention of Booker T. Washington, head of the Tuskegee Institute in Alabama. In 1896, Washington became head of the agricultural and dairy department at Tuskegee, where he remained for the rest of his long career. He died in 1943.

Read More

Liverworts, Cousins of Mosses

Posted in Interesting Plant Stories on January 8, 2014 by Barbara Thiers

Barbara M. Thiers, Ph.D., is the Patricia K. Holmgren Director of the William and Lynda Steere Herbarium and Vice President for Science Administration at The New York Botanical Garden.


Illustration from Ernst Haeckel’s Kunstformen der Natur (Art Forms of Nature), a book of illustrations of various organisms published in two volumes in 1904.

Alma Whittaker, the heroine of Elizabeth Gilbert’s recent novel The Signature of All Things, has a passion for science, especially botany, and most especially mosses. I share these passions although I have always been more captivated by liverworts, the cousins of mosses.

Mosses and liverworts were among the first groups of plants that evolved to live on land rather than in water. Because they lack the internal mechanisms for conducting water that most land plants have, they remain small so their leaves can absorb water directly from the surfaces on which they grow. Mosses and liverworts both reproduce by single-celled spores rather than seeds.

While most mosses are fairly uniform in structure, consisting of a stem with simple leaves spiraling around it, liverworts are unfettered by structural conformity. As shown in the illustration, their forms range from ribbon-like to leafy, and the leaves can be folded and divided in many ways. They release their spores by means of stalked structures that look like umbrellas or tiny brown flowers.

Read More